Yes, bigger fish like that are likely to live to at least 20 if cared for well. Even small fish can randomly live to extreme ages occasionally. My record used to be a solitary silver hatchet which I had for 17 years, but I think that's been beaten recently. Last month my last remaining red scissortail died. Unfortunately I don't have a note of exactly when I got those fish but I know I had them in a tank that I replaced in 2007, so that was over 17 years ago. I nearly always seem to end up with one fish from a group that far outlives the rest.